It has long been a desire in agricultural operations to reduce costs and increase efficiency and productivity by performing only those tasks that are needed at specific locations. For example, an agricultural field may require an application of fertilizer or chemicals, but only on certain areas of the field. The conventional method of applying the chemicals over the entire field results in unnecessary costs. In addition, current environmental concerns make excess chemical applications undesirable.
In U.S. Pat. No. 5,050,771, Hanson et al. discloses a control system in which a field may be sprayed selectively, based on a map showing areas where application is desired. An agricultural machine uses sensors to track the distance the machine travels. Checkpoints and flags provide a machine operator with means to determine position relative to the areas for application. Hanson et al. offers a method to selectively control the locations to apply chemicals in a field. However, the method requires the placement of flags and markers to give an operator a set of references. Placing these flags requires considerable effort, and results in a system that is low in accuracy and reliability. In addition, the locations for spraying must be stored in a memory. Any desired changes would require reprogramming the existing memory locations.
Recent advances in technologies, such as Global Positioning Satellite (GPS) systems and computer technologies, have paved the way for developments commonly known as precision farming. By knowing the location of an agricultural machine relative to a known terrain map, navigation of the machine can be controlled. Also, the tasks performed by the machine can be controlled in selective areas.
As an example of precision farming, Anderson, in U.S. Pat. No. 5,684,476, discloses a navigation system for an agricultural machine which uses GPS and dead reckoning technology to determine the location of the machine and correct for determined navigation errors. Anderson also discloses the use of a terrain map and checkpoints to aid in navigating the machine. However, the checkpoints are determined based on sensed operations of the machine. For example, when the GPS system determines that the machine has changed direction, a checkpoint indicating a boundary of the field is determined. Other checkpoints are determined based on sensed elevation changes, sudden turns, and the like. The system which Anderson discloses does not provide checkpoints in advance for path planning and implement control. In addition, Anderson does not provide for a central control system which provides data and checkpoints to allow multiple agricultural machines to cooperatively work in a field, providing the same or different operations.
In U.S. Pat. No. 5,712,782, Weigelt et al. discloses a method for multiple agricultural machines to communicate with a central controller. Each machine is equipped with an on-board processor to control the machine to some extent. However, Weigelt et al. does not disclose path planning or implement control by the machine processors.
The present invention is directed to overcoming one or more of the problems as set forth above.